BIRTHDAY READER SPECIAL: BUILDING A RESIN MODEL OF THE PROJECT SWORD BOOSTER ROCKET BY MARTIN

A few months ago I produced a resin kit of the Project Sword Nuclear Booster Rocket – this is a view of how it was made.

History

Way back in the 1960s I was lucky enough to receive the Nuclear Booster Rocket as a Christmas present. Unfortunately sometime in the intervening 40+ years it was lost, but recently I came across the Moonbase Central website which reminded me of it.

Looking at the prices the originals sell for on ebay ( when they do come up, which is rarely ) I knew I’d never be able to afford another. However for the last few years I have been operating a small business as a ‘garage’ model kit manufacturer, so I started looking at the possibility of making my own from scratch.

The Spacecraft Design

While most people frequenting this website will be familiar with the appearance of the toy, they may not know that it was based on a 1960 study produced by NASA’s Lewis Research Center laboratory for a manned Mars mission along with a later revision of the study authored by Thomas Widmer in 1963.

Widmer design

Subsequently an updated version appeared in Arthur C. Clarke’s book ‘Man and Space’, painted by Ed Valigursky. This version better resembled the SWORD version, with longer drop tanks and glider on the nose.

Valigursky painting

Model Design

In designing the model kit, I started by finding a photo online depicting the SWORD toy from the side and measuring it to determine the relative dimensions such as overall length compared to the width. Once I had all the necessary dimensions I started figuring out how to construct the master parts from which I would make the moulds, a part of this process being working out how big to make the model.

In the end the model size was determined by the size of the hemispherical domes of the tank ends – for these I used the tank dome from an Airfix Saturn V 3rd stage sanded smooth. The size of the rest of the model was then derived from the dimensions of this dome. Fortunately I was able to find a supply of acrylic tubing which matched the required diameters for the tanks and the core of the rocket.

Construction

While waiting for the acrylic tube to arrive, I started work on the re-entry glider. The master parts for the fuselage were made from resin castings ‘borrowed’ from another model I make, while the wings were made from plasticard with the rocket motors being bomb nosecones from an Airfix model F-16. Unlike the original toy I decided to equip the glider with a vertical fin, though of course a customer building the model could omit this if they desired.

Glider master during preparation

These parts were then used to make silicone moulds in which the production model would be cast.

The first cast resin glider out of the mould was then used to make the master of the docking collar ( the glider is removeable ) – this was made from ribbed plasticard.

Docking collar on glider

When the acrylic tube arrived I first made the mould for the fuel tanks. Each tank is made up from two end dome castings and a tubular section.

The core of the rocket is made from two identical cylindrical sections – I chose to split it into two parts primarily to reduce the size of the silicone mould needed to make the core, though it also allows the option of making different sized models with three or more rings of tanks. Again I used acrylic tube to make this mould.

The engine section was a little more complex to make. I started by making one of the radiator fins from ribbed plasticard, the ribs representing the coolant pipes, which was then moulded to produce the twelve identical fins which were then glued to the cylindrical core of the engine.

Master parts for engine, tank, and core sections

The forward conical transition was made by rolling plasticard into a cone over circular formers, then applying strips of plastic to form the ribs. The docking collar was then fixed to the narrow end of the cone.

The tail cone was made from another part of an Airfix Saturn V cut down to size, with extra detail added using plasticard.

Both nose and tail cones were deliberately made slightly oversize so they could be blended into the core body by sanding off excess resin.

Finally the exhaust nozzle was made from another piece of Airfix Saturn V plus the cap from a permanent marker !

I also made decals for the model ( along with some for other kits ).

After that it was time to get casting….

Building the model

As with all resin kits the first step is to give all the parts a wash in warm soapy water to remove any residue from casting which may affect paint adhesion. Then comes the boring bit – sanding off any excess resin left from casting. As you may guess from the number of parts this can take some time, especially as you need to ensure that all the ends are flat and true to avoid a wonky rocket !

It was then simply a case of superglueing all the bits together. I left it in several sub-assemblies to make it easier to paint.

Primed and ready for the topcoat

On resin kits I use a coat of thinned matt white enamel as a primer, with several coats as required to cover areas of filler, followed by a gloss topcoat to aid decal adhesion.

For the prototype I decided to go for silver fuel tanks rather than the toy’s blue, aiming for a more realistic appearance.

The core of the rocket was painted pure white, with various stripes added using decals, and the aft radiator panels painted a dark metallic gray. The core was then finished with a coat of matt varnish.

Once painted the fuel tanks were glued to the core – each tank has a raised strip along its length to form the mounting point. Care has to be taken to get the tanks lined up correctly both longitudinally and radially.

The Result

            The final model, 62cm long.

The kit is available for sale, and for those unsure about building resin kits I can build it for you with your own choice of colour scheme – just contact me at martin@martins-models.co.uk for details.

Cheers

Martin